package com.lzx.reggie.controller;

import com.lzx.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.UUID;

/**
 * 文件的上传和下载
 */
@RestController
@RequestMapping("/common")
@Slf4j
public class CommonController {

    @Value("${reggie.path}")
    private String basePath;

    /**
     * 文件上传
     * @param file
     * @return
     */
    @PostMapping("/upload")
    public R<String> upload(MultipartFile file) throws IOException {
        log.info(file.toString());

        //原始文件名
        String originalFilename = file.getOriginalFilename();//.png
        String suffix = originalFilename.substring(originalFilename.lastIndexOf("."));
        //使用UUID重新生成文件名，防止文件名重复造成文件覆盖
        String uuid = UUID.randomUUID().toString();//dafafafaasadwcs
        //组成完整的文件名
        String fileName = uuid + suffix;

        //创建一个目录对象
        File dir = new File(basePath);
        //判断当前目录是否存在
        if (!dir.exists()){
            //配置文件中的目录不存在，需要创建
            dir.mkdirs();
        }

        file.transferTo(new File(basePath+fileName));

        return R.success(fileName);
    }

    /**
     * 文件下载
     * @param name
     * @param response
     */
    @GetMapping("/download")
    public void download(String name, HttpServletResponse response) throws IOException {
        //1.输入流，通过输入流读取文件的内容
        FileInputStream fileInputStream = new FileInputStream(new File(basePath+ name));

        //2.输出流，通过输出流将文件写回浏览器，然后展示
        ServletOutputStream outputStream = response.getOutputStream();
        //下载的是图片文件，设置一下我们响应回去的到底是什么文件
        response.setContentType("image/jpeg");
        //开始写操作
        int len=0;
        byte[] bytes=new byte[1024];
        while ((len=fileInputStream.read(bytes))!=-1){
            outputStream.write(bytes,0,len);
            outputStream.flush();
        }

        //3.关闭流
        outputStream.close();
        fileInputStream.close();
    }

}
